Which pairs of fractions can be added using the given common denominators? Write a pair of fractions on each blank to show their common denominator.
Use the pairs of fractions in the box. Not all answer choices will be used.
1.7
2' 9
3 2
46
4 6
5' 10
13
3'5
5 2
6' 9
3 1
20' 3
124
3'9
Common denominator: 24
Common denominator: 15
Common denominator: 9

Agroup of student volunteers participates in a study designed to assess several behavioral interventions for improving output in a repetitive task. prior to the beginning of the study, all volunteers unknowingly observed, and their output is measured. at the beginning of the study, prior to any intervention, the volunteers perform the same task under the observation of a study administrator, and their overall output increases. which of the following terms describes this phenomenon? a. simpson's paradox b. hawthorne effect are d. novelty effect d. pygmalion effect e. observer-expectancy effect